Inital commit of the first SSL module \o/ \o/ \o/ Also Ommeh's first official svn commit \o/

git-svn-id: http://svn.inspircd.org/repository/trunk/inspircd@2842 e03df62e-2008-0410-955e-edbf42e46eb7

1 files changed, 524 insertions, 0 deletions

diff --git a/src/modules/extra/m_ssl_gnutls.cpp b/src/modules/extra/m_ssl_gnutls.cpp
new file mode 100644
index 000000000..ddb32b5f0
--- /dev/null
+++ b/src/modules/extra/m_ssl_gnutls.cpp
@@ -0,0 +1,524 @@
+#include <string>
+#include <vector>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <gnutls/gnutls.h>
+
+#include "users.h"
+#include "channels.h"
+#include "modules.h"
+#include "helperfuncs.h"
+#include "socket.h"
+#include "hashcomp.h"
+
+/* $ModDesc: Provides SSL support for clients */
+/* $CompileFlags: `libgnutls-config --cflags` */
+/* $LinkerFlags: -L/usr/local/lib -Wl,--rpath -Wl,/usr/local/lib -L/usr/lib -Wl,--rpath -Wl,/usr/lib -lgnutls */
+
+enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
+
+class issl_session
+{
+public:
+	gnutls_session_t sess;
+	issl_status status;
+	std::string outbuf;
+	int inbufoffset;
+	char* inbuf;
+	int fd;
+};
+
+class ModuleSSL : public Module
+{
+	Server* Srv;
+	ServerConfig* SrvConf;
+	ConfigReader* Conf;
+	
+	std::vector<int> listenports;
+	
+	int inbufsize;
+	issl_session sessions[MAX_DESCRIPTORS];
+	
+	gnutls_certificate_credentials x509_cred;
+	gnutls_dh_params dh_params;
+	
+	std::string keyfile;
+	std::string certfile;
+	std::string cafile;
+	std::string crlfile;
+	int dh_bits;
+	
+ public:
+	
+	ModuleSSL(Server* Me)
+		: Module::Module(Me)
+	{
+		Srv = Me;
+		SrvConf = Srv->GetConfig();
+		Conf = new ConfigReader;
+		
+		// Not rehashable...because I cba to reduce all the sizes of existing buffers.
+		inbufsize = SrvConf->NetBufferSize;
+		
+		gnutls_global_init(); // This must be called once in the program
+
+		if(gnutls_certificate_allocate_credentials(&x509_cred) != 0)
+			log(DEBUG, "m_ssl_gnutls.so: Failed to allocate certificate credentials");
+
+		// Guessing return meaning
+		if(gnutls_dh_params_init(&dh_params) < 0)
+			log(DEBUG, "m_ssl_gnutls.so: Failed to initialise DH parameters");
+
+		OnRehash("");
+
+		// Void return, guess we assume success
+		gnutls_certificate_set_dh_params(x509_cred, dh_params);
+	}
+	
+	virtual void OnRehash(std::string param)
+	{
+		delete Conf;
+		Conf = new ConfigReader;
+		
+		for(unsigned int i = 0; i < listenports.size(); i++)
+		{
+			SrvConf->DelIOHook(listenports[i]);
+		}
+		
+		listenports.clear();
+		
+		for(int i = 0; i < Conf->Enumerate("bind"); i++)
+		{
+			// For each <bind> tag
+			if((Conf->ReadValue("bind", "type", i) == "clients") && (Conf->ReadValue("bind", "ssl", i) == "gnutls"))
+			{
+				// Get the port we're meant to be listening on with SSL
+				unsigned int port = Conf->ReadInteger("bind", "port", i, true);
+				SrvConf->AddIOHook(port, this);
+				
+				// We keep a record of which ports we're listening on with SSL
+				listenports.push_back(port);
+				
+				log(DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %d", port);
+			}
+		}
+		
+		cafile	= Conf->ReadValue("gnutls", "cafile", 0);
+		crlfile	= Conf->ReadValue("gnutls", "crlfile", 0);
+		certfile	= Conf->ReadValue("gnutls", "certfile", 0);
+		keyfile	= Conf->ReadValue("gnutls", "keyfile", 0);
+		dh_bits	= Conf->ReadInteger("gnutls", "dhbits", 0, false);
+		
+		if(cafile == "")
+			cafile = "conf/ca.pem";
+			
+		if(crlfile == "")
+			crlfile = "conf/crl.pem";
+			
+		if(certfile == "")
+			certfile = "conf/cert.pem";
+			
+		if(keyfile == "")
+			keyfile = "conf/key.pem";
+			
+		if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
+			dh_bits = 1024;
+		
+		if(gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM) < 0)
+			log(DEBUG, "m_ssl_gnutls.so: Failed to set X.509 trust file: %s", cafile.c_str());
+			
+		if(gnutls_certificate_set_x509_crl_file (x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM) < 0)
+			log(DEBUG, "m_ssl_gnutls.so: Failed to set X.509 CRL file: %s", crlfile.c_str());
+		
+		// Guessing on the return value of this, manual doesn't say :|
+		if(gnutls_certificate_set_x509_key_file (x509_cred, certfile.c_str(), keyfile.c_str(), GNUTLS_X509_FMT_PEM) < 0)
+			log(DEBUG, "m_ssl_gnutls.so: Failed to set X.509 certificate and key files: %s and %s", certfile.c_str(), keyfile.c_str());	
+			
+ 		// Generate Diffie Hellman parameters - for use with DHE
+		// kx algorithms. These should be discarded and regenerated
+		// once a day, once a week or once a month. Depending on the
+		// security requirements.
+		
+		if(gnutls_dh_params_generate2(dh_params, dh_bits) < 0)
+			log(DEBUG, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits)", dh_bits);
+	}
+	
+	virtual ~ModuleSSL()
+	{
+		delete Conf;
+		gnutls_dh_params_deinit(dh_params);
+		gnutls_certificate_free_credentials(x509_cred);
+		gnutls_global_deinit();
+	}
+	
+	virtual Version GetVersion()
+	{
+		return Version(1, 0, 0, 0, 0);
+	}
+
+	void Implements(char* List)
+	{
+		List[I_OnRawSocketAccept] = List[I_OnRawSocketClose] = List[I_OnRawSocketRead] = List[I_OnRawSocketWrite] = 1;
+		List[I_OnSyncUserMetaData] = List[I_OnDecodeMetaData] = List[I_OnUserQuit] = List[I_OnRehash] = List[I_OnWhois] = 1;
+	}
+
+	virtual void OnRawSocketAccept(int fd, std::string ip, int localport)
+	{
+		issl_session* session = &sessions[fd];
+	
+		session->fd = fd;
+		session->inbuf = new char[inbufsize];
+		session->inbufoffset = 0;
+	
+		gnutls_init(&session->sess, GNUTLS_SERVER);
+
+		gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
+		gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
+		gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
+		gnutls_dh_set_prime_bits(session->sess, dh_bits);
+		gnutls_transport_set_ptr(session->sess, (gnutls_transport_ptr_t) fd); // Give gnutls the fd for the socket.
+		
+		Handshake(session);
+	}
+
+	virtual void OnRawSocketClose(int fd)
+	{
+		CloseSession(&sessions[fd]);
+	}
+	
+	virtual int OnRawSocketRead(int fd, char* buffer, unsigned int count, int &readresult)
+	{
+		issl_session* session = &sessions[fd];
+		
+		if(!session->sess)
+		{
+			log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: No session to read from");
+			readresult = 0;
+			CloseSession(session);
+			return 1;
+		}
+		
+		log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead(%d, buffer, %u, %d)", fd, count, readresult);
+		
+		if(session->status == ISSL_HANDSHAKING_READ)
+		{
+			// The handshake isn't finished, try to finish it.
+			
+			if(Handshake(session))
+			{
+				// Handshake successfully resumed.
+				log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: successfully resumed handshake");
+			}
+			else
+			{
+				// Couldn't resume handshake.	
+				log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: failed to resume handshake");
+				return -1;
+			}
+		}
+		else if(session->status == ISSL_HANDSHAKING_WRITE)
+		{
+			log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: handshake wants to write data but we are currently reading");
+			return -1;
+		}
+		
+		// If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
+		
+		if(session->status == ISSL_HANDSHAKEN)
+		{
+			// Is this right? Not sure if the unencrypted data is garaunteed to be the same length.
+			// Read into the inbuffer, offset from the beginning by the amount of data we have that insp hasn't taken yet.
+			log(DEBUG, "m_ssl_gnutls.so: gnutls_record_recv(sess, inbuf+%d, %d-%d)", session->inbufoffset, inbufsize, session->inbufoffset);
+			
+			int ret = gnutls_record_recv(session->sess, session->inbuf + session->inbufoffset, inbufsize - session->inbufoffset);
+
+			if(ret == 0)
+			{
+				// Client closed connection.
+				log(DEBUG, "m_ssl_gnutls.so: Client closed the connection");
+				readresult = 0;
+				CloseSession(session);
+				return 1;
+			}
+			else if(ret < 0)
+			{
+				if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
+				{
+					log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: Not all SSL data read: %s", gnutls_strerror(ret));
+					return -1;
+				}
+				else
+				{
+					log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: Error reading SSL data: %s", gnutls_strerror(ret));
+					readresult = 0;
+					CloseSession(session);
+				}
+			}
+			else
+			{
+				// Read successfully 'ret' bytes into inbuf + inbufoffset
+				// There are 'ret' + 'inbufoffset' bytes of data in 'inbuf'
+				// 'buffer' is 'count' long
+				
+				unsigned int length = ret + session->inbufoffset;
+		
+				log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: Read %d bytes, now have %d waiting to be passed up", ret, length);
+						
+				if(count <= length)
+				{
+					memcpy(buffer, session->inbuf, count);
+					// Move the stuff left in inbuf to the beginning of it
+					memcpy(session->inbuf, session->inbuf + count, (length - count));
+					// Now we need to set session->inbufoffset to the amount of data still waiting to be handed to insp.
+					session->inbufoffset = length - count;
+					// Insp uses readresult as the count of how much data there is in buffer, so:
+					readresult = count;
+				}
+				else
+				{
+					// There's not as much in the inbuf as there is space in the buffer, so just copy the whole thing.
+					memcpy(buffer, session->inbuf, length);
+					// Zero the offset, as there's nothing there..
+					session->inbufoffset = 0;
+					// As above
+					readresult = length;
+				}
+			
+				log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: Passing %d bytes up to insp:");
+				Srv->Log(DEBUG, std::string(buffer, readresult));
+			}
+		}
+		else if(session->status == ISSL_CLOSING)
+		{
+			log(DEBUG, "m_ssl_gnutls.so: OnRawSocketRead: session closing...");
+			readresult = 0;
+		}
+		
+		return 1;
+	}
+	
+	virtual int OnRawSocketWrite(int fd, char* buffer, int count)
+	{		
+		issl_session* session = &sessions[fd];
+		const char* sendbuffer = buffer;
+
+		if(!session->sess)
+		{
+			log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: No session to write to");
+			CloseSession(session);
+			return 1;
+		}
+		
+		if(session->status == ISSL_HANDSHAKING_WRITE)
+		{
+			// The handshake isn't finished, try to finish it.
+			
+			if(Handshake(session))
+			{
+				// Handshake successfully resumed.
+				log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: successfully resumed handshake");
+			}
+			else
+			{
+				// Couldn't resume handshake.	
+				log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: failed to resume handshake"); 
+			}
+		}
+		else if(session->status == ISSL_HANDSHAKING_READ)
+		{
+			log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: handshake wants to read data but we are currently writing");
+		}
+
+		log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Adding %d bytes to the outgoing buffer", count);		
+		session->outbuf.append(sendbuffer, count);
+		sendbuffer = session->outbuf.c_str();
+		count = session->outbuf.size();
+
+		if(session->status == ISSL_HANDSHAKEN)
+		{
+			log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Trying to write %d bytes:", count);
+			Srv->Log(DEBUG, session->outbuf);
+			
+			int ret = gnutls_record_send(session->sess, sendbuffer, count);
+		
+			if(ret == 0)
+			{
+				log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Client closed the connection");
+				CloseSession(session);
+			}
+			else if(ret < 0)
+			{
+				if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
+				{
+					log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Not all SSL data written: %s", gnutls_strerror(ret));
+				}
+				else
+				{
+					log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Error writing SSL data: %s", gnutls_strerror(ret));
+					CloseSession(session);					
+				}
+			}
+			else
+			{
+				log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: Successfully wrote %d bytes", ret);
+				session->outbuf = session->outbuf.substr(ret);
+			}
+		}
+		else if(session->status == ISSL_CLOSING)
+		{
+			log(DEBUG, "m_ssl_gnutls.so: OnRawSocketWrite: session closing...");
+		}
+		
+		return 1;
+	}
+
+	virtual void OnUserQuit(userrec* user, std::string reason)
+	{
+		CloseSession(&sessions[user->fd]);
+	}
+	
+	// :kenny.chatspike.net 320 Om Epy|AFK :is a Secure Connection
+	virtual void OnWhois(userrec* source, userrec* dest)
+	{
+		if(dest->GetExt("ssl"))
+		{
+			WriteServ(source->fd, "320 %s %s :is a Secure Connection", source->nick, dest->nick);
+		}
+	}
+	
+	virtual void OnSyncUserMetaData(userrec* user, Module* proto, void* opaque, std::string extname)
+	{
+		// check if the linking module wants to know about OUR metadata
+		if(extname == "ssl")
+		{
+			// check if this user has an swhois field to send
+			if(user->GetExt(extname))
+			{
+				// call this function in the linking module, let it format the data how it
+				// sees fit, and send it on its way. We dont need or want to know how.
+				proto->ProtoSendMetaData(opaque, TYPE_USER, user, extname, "ON");
+			}
+		}
+	}
+	
+	virtual void OnDecodeMetaData(int target_type, void* target, std::string extname, std::string extdata)
+	{
+		// check if its our metadata key, and its associated with a user
+		if ((target_type == TYPE_USER) && (extname == "ssl"))
+		{
+			userrec* dest = (userrec*)target;
+			// if they dont already have an ssl flag, accept the remote server's
+			if (!dest->GetExt(extname))
+			{
+				dest->Extend(extname, "ON");
+			}
+		}
+	}
+	
+	bool Handshake(issl_session* session)
+	{		
+		int ret = gnutls_handshake(session->sess);
+      
+      if(ret < 0)
+		{
+			if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
+			{
+				// Handshake needs resuming later, read() or write() would have blocked.
+				
+				if(gnutls_record_get_direction(session->sess) == 0)
+				{
+					// gnutls_handshake() wants to read() again.
+					session->status = ISSL_HANDSHAKING_READ;
+					log(DEBUG, "m_ssl_gnutls.so: Handshake needs resuming (reading) later, error string: %s", gnutls_strerror(ret));
+				}
+				else
+				{
+					// gnutls_handshake() wants to write() again.
+					session->status = ISSL_HANDSHAKING_WRITE;
+					log(DEBUG, "m_ssl_gnutls.so: Handshake needs resuming (writing) later, error string: %s", gnutls_strerror(ret));
+					MakePollWrite(session);	
+				}
+			}
+			else
+			{
+				// Handshake failed.
+				CloseSession(session);
+			   log(DEBUG, "m_ssl_gnutls.so: Handshake failed, error string: %s", gnutls_strerror(ret));
+			   session->status = ISSL_CLOSING;
+			}
+			
+			return false;
+		}
+		else
+		{
+			// Handshake complete.
+			log(DEBUG, "m_ssl_gnutls.so: Handshake completed");
+			
+			// This will do for setting the ssl flag...it could be done earlier if it's needed. But this seems neater.
+			Srv->FindDescriptor(session->fd)->Extend("ssl", "ON");
+			
+			session->status = ISSL_HANDSHAKEN;
+			
+			MakePollWrite(session);
+			
+			return true;
+		}
+	}
+	
+	void MakePollWrite(issl_session* session)
+	{
+		OnRawSocketWrite(session->fd, NULL, 0);
+	}
+	
+	void CloseSession(issl_session* session)
+	{
+		if(session->sess)
+		{
+			gnutls_bye(session->sess, GNUTLS_SHUT_WR);
+			gnutls_deinit(session->sess);
+		}
+		
+		if(session->inbuf)
+		{
+			delete[] session->inbuf;
+		}
+		
+		session->outbuf.clear();
+		session->inbuf = NULL;
+		session->sess = NULL;
+		session->status = ISSL_NONE;
+	}
+};
+
+class ModuleSSLFactory : public ModuleFactory
+{
+ public:
+	ModuleSSLFactory()
+	{
+	}
+	
+	~ModuleSSLFactory()
+	{
+	}
+	
+	virtual Module * CreateModule(Server* Me)
+	{
+		return new ModuleSSL(Me);
+	}
+};
+
+
+extern "C" void * init_module( void )
+{
+	return new ModuleSSLFactory;
+}
+